FIELD OF THE INVENTION

The present invention is enclosed in the area of the detection of forest fires, in particular with detection of the approximation of forest fires, and also further including fire countermeasure means such as sprinkling means which actuate based on the detection of a forest fire.

PRIOR ART

Solutions exist in the art where the approximation of a forest fire is detected by a variation in the measurements provided by one sensor, for instance an infrared sensor, and sprinkling means are consequently initiated, in order to wet the nearby area and affect the propagation of the fire. Such is the case of patent application US 2019/0001170, which discloses a specific system which also focuses on the operation of the sprinkling means.

Other kind of solutions exist containing more advanced details as regards the detection and propagation of a forest fire, as is the case of patent applications EP3058556 and EP1817759, which focus on the processing of image data.

Thus, the solutions known in the art are either very simplified and stand alone or based on very complex systems which require high computer processing and are significantly prone to the ambient / image conditions available at a certain moment. The present solution innovatively overcomes such issues.

SUMMARY OF THE INVENTION It is therefore an object of the present invention a device for the detection of a flame condition, in particular for the detection of a forest fire, based on flame condition data, characterised in that it is configured to: receive flame condition data issued by at least one flame detection node from a plurality of flame detection nodes, wherein such data is on based data obtained from at least one flame sensor provided in such flame detection node, and based on local environmental data, determine a value corresponding to a risk of forest fire and, based on such value, issue a command to alter at least one parameter of operation of the plurality of flame condition detection nodes.

Such device therefore provides for an optimal operation as regards the detection of a flame condition, since an awareness of the device for the detection of the flame condition may be raised as a consequence of the determination of a value corresponding to a risk of forest fire, for instance upon a raise in such value when compared to a previously determined value (which may be above a certain percentage) or when such value is above a predefined threshold. The referred awareness is substantiated by the issue of a command to alter the at least one parameter of operation of a plurality of flame condition detection nodes, which may form a network of node devices connected by cable or wirelessly.

Such solution comprising a detection device and a plurality of flame detection nodes is substantiated in another object of the present invention - which will be described in more detail in the detailed description - and which is a system for the detection of a flame condition, in particular for the detection of a forest fire, based on flame condition data.

Moreover, as regards the detection device, the at least one parameter of operation may consist of frequency of obtainment of flame condition data and/or the frequency of transmission of flame condition data, thereby providing for cases in which the referred awareness may be adapted to the determined value of risk, namely by raising the frequency of obtainment of flame condition data, to more frequently monitor changes in the obtained values, and the frequency of transmission / receipt of flame condition data, so as to more frequently be able to detect a flame condition in the detection device. Preferably, the data obtained from at least one flame sensor comprises temperature data.

In particular, the environmental data may comprise local temperature, relative humidity, local barometric pressure, rain and/or local wind data, wherein the environmental data is prediction data or real-time data. Thus, the operation of the detection device may be adapted based on information which is presently being obtained - in real-time - or based on information which results from a prediction which was previously obtained. In addition, the environmental data is local, therefore providing a higher certainty as regards the obtained values. The detection device may thus further comprise one or more sensors configured to obtain the environmental data. Alternatively or cumulatively, the detection device may obtain environmental data corresponding to one or more remote sensors, which still referto an area which includes the area in which the flame condition is to be detected.

It is also an object of the present invention a forest fire countermeasure system which comprises: the detection device of the present invention, in any of its described embodiments, or the detection system of the present invention, in any of its described embodiments, and countermeasure means, the countermeasure means being configured to be actuated upon a detection of flame condition by the detection device, the countermeasure means preferably comprising sprinkling means which are actuated upon a detection of flame condition by the detection device. Such countermeasure system enables to provide a fire-fighting action, namely with the provision of water, against a detected nearby flame condition, or upon the detection of the approach of such flame condition. The sprinkling means may comprise several sprinkling outputs, the outputs being provided in several different locations, in order to improve the countermeasures coverage area.

Thus, the detection device or system of the present invention, as well as the countermeasure system, are also able to emit (or allow the emission of) warnings to alert civil protection entities and property owners, and can be used to protect small villages and its inhabitants, isolated houses and industries, among others.

It is also an object of the present invention a method for the detection of a flame condition, in particular for the detection of a forest fire, wherein it comprises: receiving flame condition data issued by at least one flame detection node from a plurality of flame detection nodes, wherein such data is based on data obtained from at least one flame sensor provided in such flame detection node, and based on local environmental data, determining a value corresponding to a risk of forest fire and, based on such value, issue a command to alter at least one parameter of operation of the plurality of flame condition detection nodes.

Such method has associated advantages, which are the same as the corresponding detection device previously described. DESCRIPTION OF FIGURES

Figure 1 - a representation of the method of the present invention, including receiving flame condition data issued by at least one flame detection node from a plurality of flame detection nodes (110), wherein such data is based on data obtained from at least one flame sensor provided in such flame detection node (101) and, based on local environmental data (102), determining a value corresponding to a risk of forest fire and, based on such value, issue a command to alter at least one parameter of operation of the plurality of flame condition detection nodes (111).

Figure 2 - a representation of the detection system of the present invention, in particular where a flame detection node (14) comprises an aim (30). In turn, the aim comprises i) two tubes (31, 32) arranged at an angle equal to the field-of-view (FOV, 13) or, alternatively, ii) two oblong holes formed in a support material. The vertical FOV (13) is formed by the angle (a) between a minimum detection distance (10) and a maximum detection distance (11). An aim may be attached to the side of the flame sensor of the flame detection node, or at least aligned with the flame sensor, thereby providing a facilitated installation and calibration of the flame sensors. In the representation of Figure 2, the fire (12) is detected as it is within the FOV (13) of the flame sensor.

Figure 3 - representation of a tubular aim (30) according to the present invention.

Figures 4a and 4b - representation of two views of a pyramidal aim (40) according to the present invention.

Figures 5a and 5b - representation of two views of a window aim (50) according to the present invention. Figure 6 - a representation of an embodiment of the countermeasure system (600) of the present invention, comprising the system for the detection of a flame condition which in turn comprises the detection device (68) and two flame detection nodes (64). An angle a equal to a field-of-view is also represented (63). In addition, the countermeasure system (600) comprises a plurality of other elements which provide for an enhanced operation. In particular, a water supply (66) is connected by means of plumbing (65) to a sprinkler (61). In between, it is connected an electric valve (67) in turn connected to two pressure sensors (60). The electric valve (67) is connected to the detection device (68), which is configured to control its operation. In addition, the connection between the detection nodes (64) and the detection device (68) is provided by a cabled communication network (62). Moreover, the detection device (68) may comprise an antenna (69), suitable to remotely transmit and receive information.

DETAILED DESCRIPTION

The more general and advantageous configurations of the present invention are described in the Summary of the invention. Such configurations are detailed below in accordance with other advantageous and/or preferred embodiments of implementation of the present invention.

The detection device object of the present invention may comprise further inventive aspects, which configure themselves inventions, irrespective of the feature of based on local environmental data (102), determine a value corresponding to a risk of forest fire and, based on such value, issue a command to alter at least one parameter of operation of the plurality of flame condition detection nodes (111). As regards the data obtained from at least one flame sensor, it comprises temperature data, the sensor is a matrix thermal sensor, preferably a far infrared sensor array and/or a thermal camera. Consequently, the flame condition data may comprise: temperature and/or coordinates of a pixel with the highest temperature, designated as the hottest pixel, a number of pixels with temperatures above a predefined temperature threshold, and/or an average temperature of all the pixels. In a related inventive aspect, the flame condition data comprises temperature of a hottest pixel and the device is further configured to compare each received flame condition data from a flame condition detection node with a predefined temperature threshold, and thereby determine the flame condition. It consists of a simple and effective way to obtain the flame condition data, which otherwise could require image data and result in a complex solution for the detection of a flame condition.

In another related inventive aspect, which enhances the one described immediately above, the flame condition data further comprises a number of pixels with temperatures above a predefined threshold and the device is further configured to compare the received number of pixels with temperatures above a predefined temperature threshold with a predefined number of pixels threshold, such comparison being preferably performed only if the received flame condition data from a flame condition detection node is above the predefined temperature threshold.

A further embodiment regarding the detection system is subsequently described.

In an advantageous aspect of the detection system of the present invention, it comprises the detection device as previously described, in any of its embodiments, and a plurality of flame detection nodes, each of the flame detection nodes comprising at least one flame sensor and being configured to transmit flame condition data based on data obtained from the at least one flame sensor. ln another advantageous embodiment of the detection system of the present invention, the flame detection node comprises an aim, wherein at least one of the flame detection nodes comprises an aim, the aim being so configured that it provides an angle equal to the field-of-view (FOV) of the flame sensor, wherein said FOV is formed by the angle between a minimum detection distance and a maximum detection distance of the flame sensor and, preferably, such aim is attached to the side, or at least aligned with, the flame sensor. By attaching the aim in such fashion, it provides a facilitated installation and calibration of the flame sensors.

The aim may have a variety of shapes such as tubular, pyramidal or window.

A tubular aim (BO) is presented in Figure 3, and it comprises i) two tubes (31, 32) arranged at an angle equal to the field-of-view (FOV, 13) or, alternatively, ii) two oblong holes formed in a support material. The FOV (13) is formed by the angle (a) between a minimum detection distance (10) and a maximum detection distance (11). The two tubes are arranged at an angle equal to the field-of-view (FOV) of the flame sensor, wherein said FOV is formed by the angle between a minimum detection distance and a maximum detection distance of the flame sensor and, preferably, such aim is attached to the side, or at least aligned with, the flame sensor.

A similar tubular aim may be positioned horizontally in order to assess the horizontal alignment of the flame sensor, the angle between these two tubes being equal to the horizontal FOV of the flame sensor. Two tubes forming the tubular aim, one vertical and one horizontal - as provided in Figure 3 - , can be done in one single piece of material and used to perform a horizontal assessment and a vertical alignment of the flame sensors.

A pyramidal aim (40) is presented in Figures 4a and 4b, providing an enhanced alternative to the tubular aim, while having the same operating principle. Such alternative provides the advantage of displaying the 3D detection field of the sensor. The pyramidal aim comprises a troncopiramidal opening, with a lesser size (41) opening to a wider size (42). The widening from the lesser size (41) to the wider size of the opening is arranged at an angle equal to the horizontal and vertical field-of-view (FOV) of the flame sensor, wherein said vertical FOV is formed by the angle between a minimum detection distance and a maximum detection distance of the flame sensor and, preferably, such aim is attached to the side, or at least aligned with, the flame sensor. The horizontal FOV may be different from the vertical FOV, depending on the used sensor.

A window aim (52) is presented in Figures 5a and 5b, providing a suitable alternative to the tubular and pyramidal aims, while having the same operating principle. The window aim (52) has two parallel plates, a first plate with a lesser size opening (50) and a second plate with a wider size opening (51). The two plates are separated by a support plate. The relation between the lesser size opening (50) of the first plate and the wider size opening (51) of the second plate, together with the separation provided by the support plate is such that it is arranged at an angle equal to the horizontal and vertical field-of-view (FOV) of the flame sensor, wherein said vertical FOV is formed by the angle between a minimum detection distance and a maximum detection distance of the flame sensor and, preferably, such aim is attached to the side, or at least aligned with, the flame sensor.

Further embodiments regarding the countermeasures system are subsequently described.

In an inventive aspect of the countermeasures system of the present invention, it is further configured to, upon determination of a flame condition based on a predefined temperature threshold - wherein such determination may be provided by determining the number of pixels above a predefined temperature threshold -, issue an alarm, the alarm preferably comprising sound and/or the transmission of a remote message. It therefore is able to issue alarms, and thereby warn one or more users of a flame condition, such as a warning to an owner of a monitored property that a flame condition - and thus, a forest fire - has been detected in the property / surroundings of the property, in particular the flame detection nodes from which the flame condition data is obtained being installed in such property.

In another inventive aspect of the countermeasures system of the present invention, it is further configured to actuate the countermeasure means only upon determination of a flame condition based on a predefined number of pixels above a predefined temperature threshold. It thus provides two levels of detection of a potential flame condition, thereby refining its operation and reducing a number of false positive detections.

Moreover, the countermeasure means may further comprise a tank suitable for comprising water configured to feed the sprinkling means, the countermeasure system preferably further comprising means to determine the tank current level of water.

In another embodiment, the countermeasures system may further comprise at least one electric valve, at least one electric pump, piping and at least one electric motor so arranged to control the provision of water to the sprinkling means.

Further embodiments regarding the method of the present invention are subsequently described. Such embodiments have associated advantages, which are the same as the corresponding detection device embodiments previously described.

In an inventive aspect of the method of the present invention, the at least one parameter of operation consists of frequency of obtainment of flame condition data and/or the frequency of transmission of flame condition data. ln another inventive aspect of the method of the present invention, the environmental data comprises local temperature, relative humidity, local barometric pressure, rain and/or local wind data, wherein the environmental data is prediction data or real-time data.

In yet another inventive aspect of the method of the present invention, it further comprises: obtaining the environmental data from one or more local sensors configured to obtain the environmental data, and/or obtaining remote environmental data corresponding to a local area in which the flame condition is to be detected.

In addition, and as regards the method of the present invention, the data obtained from at least one flame sensor comprises temperature data.

In addition, and as regards the method of the present invention, the sensor is a matrix thermal sensor, preferably a far infrared thermal array and/or a thermal camera.

In another embodiment regarding the method of the present invention, the flame condition data comprises: temperature and/or coordinates of a pixel with the highest temperature, designated as the hottest pixel, a number of pixels with temperatures above a predefined temperature threshold, and/or an average temperature of all the pixels.

In another embodiment of the method of the present invention, the flame condition data comprises temperature of a hottest pixel and the system is further configured to compare each received flame condition data from a flame condition detection node with a predefined temperature threshold, and thereby determine the flame condition.

In another embodiment of the method of the present invention, which relates to a particular case of that above described, the flame condition data further comprises a number of pixels with temperatures above a predefined threshold and the system is further configured to compare the number of pixels with temperatures above a predefined temperature threshold with a predefined number of pixels threshold, such comparison being preferably performed only if the flame condition data from a flame condition detection node received by the aggregation node - which comprises temperature of a hottest pixel - is above the predefined temperature threshold.

EMBODIMENTS

Several specific embodiments of the objects of the present invention are described.

The detection system of the present invention comprises a detection device, which may be referred as a single Data Aggregation Node and a plurality of Flame Detection Nodes. The number of flame detection nodes will depend on the perimeter to protect. There is no requirement that the Data Aggregation Node is provided in the vicinity of the Flame Detection Nodes, which may communicate remotely with the Data Aggregation Node. Yet, a solution in which the Data Aggregation Node is in the vicinity of the Flame Detection Nodes is herein provided.

As regards the countermeasures system, it may comprise a set of electrical valves and several output watering systems connected to the water tank, with one electrical valve for each output watering system, one water pressure sensor at a water input - which may be the water tank or another water source - and one water pressure sensor for each watering output. -IB-

Each Flame Detection Node may be composed by a flame detection sensor and a microcontroller that performs processing functions. The flame detection sensor may consist of a matrix thermal sensor, like a Far Infrared Thermal Sensor Array or a Thermal Camera. The Flame Detection Node may comprise several interfaces which are connected to the microcontroller:

• Interface with secondary sensors: like fire flickering sensors, used to avoid false alarms or false positives,

• interface for communication with a Data Aggregation Node: data sent to a Data Aggregation node using a reliable and redundant communication protocol,

• an aim to easily set the a sensor orientation and field calibration, although in such case not connected to the microcontroller.

As regards the Data Aggregation Node, and in the same way as described for the Flame Detection node, it comprises a microcontroller that performs processing functions, and further contains several interfaces:

• interface for communication with Flame Detection nodes: The Data Aggregation node receives and processes information from Flame Detection nodes, based on a cabled or wireless, WAN or LAN, communication protocol, and such protocol being reliable and redundant,

• interface with an environmental sensor: The Data Aggregation node may be equipped with environmental sensors that measure ambient temperature, relative humidity and barometric pressure. Using both the integrated sensors and rain and wind information, such node is capable of calculating the forest fire risk value, using a method such as Fire Weather Index (FWI). For instance, when the calculated risk value is high, the system is made more aware to changes in the measured values (as previously described), • interface with the Internet: to be able to send alarms, and to allow real-time monitoring and also remote activation, the Data Aggregation system is connected to the Internet.

The Data Aggregation node is also capable of performing self-diagnostic procedures and send alarms to a user if any anomaly (such as a drop of communication with a Flame Detection node or low water pressure) is detected. The communication between all Flame Detection nodes is tested periodically as well as the well-functioning of the flame sensors.

As regards the countermeasures system, it may further comprise several interfaces:

• interface for actuators and sensor for actuating the countermeasures: The Data Aggregation node is equipped with several outputs that are able to control equipment such as electric valves, electric pumps or electric motors to activate fire containment measures like, for example, a sprinkler system. The system is also equipped with several inputs that can be used for several uses like sensing water pressure in the previously mentioned sprinkler system, measuring the water level in a tank, among others.

As explained earlier, communication is provided between Flame Detection Nodes and the Data Aggregation node, comprising the temperature of the hottest pixel, its coordinates, the number of pixels with temperatures above a certain threshold (defined by the Data Aggregation node) and the average temperature of all the pixels.

Flame detection may then be based on a threshold algorithm and there are two kinds of thresholds: temperature thresholds and pixel thresholds. Every time a message is received in the Data Aggregation node, it is compared the maximum temperature detected with the aforementioned temperature threshold. If the maximum temperature is above this threshold the Data Aggregation node compares the number of pixels with temperatures above the temperature threshold with the pixel thresholds mentioned earlier. There are two kinds of pixel thresholds, one for sending alarms and other for actuating countermeasures. If the number of pixels is above the first threshold, the system sends an alarm and if it is above the second one it actuates the countermeasures (in the case of a countermeasures system) to avoid the propagation of the fire that has been detected. The countermeasures stay activated for as long as the fire is detected and for a pre-defined and configurable time period after the fire is extinguished no longer detected.

The referred thresholds are reconfigurable, for instance based on characteristics of the place of installation.

Both the Data Aggregation Node and the Flame Detection Node, are powered by DC current setups which are provided by a battery which may be connected to the electrical grid at all times. This allows the nodes to be powered even if the electrical grid fails.

Communication between nodes may use a wired protocol, a wireless protocol or, preferably, both. This allows the node to node communication to be more robust and reliable, since one of the protocols can fail and all the nodes are still able to communicate with each other. Suitable protocols consist of:

• Wireless Protocols: Wi-Fi, Bluetooth, LoRa,

• Wired protocols: CAN-bus, RS-485, Ethernet.

Node to Internet communication: The Node to Internet communication, in order to be robust and reliable, may also use a set of two different communication protocols in order to keep the system working if one of these two protocols fails, in such case consisting of wireless protocols:

• LoRa/LoRaWAN, Sigfox, GSM, LTE, 5G

The device or system may further integrate a web application to receive alarms and to provide the end user with the capability of monitoring all its parameters such as the state of all Flame Detection Nodes. This application also provides the capability of manual activation of countermeasures, even if not in the physical presence of the system. The application may also provide the fire risk information in order for the end user to take extra precautions in high fire risk days.

The countermeasures system may have three cumulative and different ways of actuating countermeasures:

• Automatic: using the algorithm for fire detection and extinction, the system is able to automatically actuate countermeasures in order to sustain the advance of flame fronts.

• Manual: the system's available countermeasures can be manually activated in the case of the user wanting to.

• Remote: Using the web application mentioned earlier, one can activate or deactivate the necessary countermeasures, even if it's not next to the system.

Every time a flame condition is detected, the countermeasures system sounds an alarm to warn the owner of the property that a fire has been detected in the surroundings of the property.

The countermeasures system is also able to send an electronic alarm to the owner's cell phone to warn him in the eventuality that he is not present in the fteaf the property. As will be clear to one skilled in the art, the present invention should not be limited to the embodiments described herein, and a number of changes are possible which remain within the scope of the present invention.

Of course, the preferred embodiments shown above are combinable, in the different possible forms, being herein avoided the repetition of all such combinations.